Switch resetting mechanism



J 1950 A. G. FORSBERG 0,

SWITCH RESETTING MECHANISM Filed July 19, 1948 Axel Gunnar Forsberg JNVENTOR.

WW FML Patented June 6, 1950 UNITED STATES PATENT OFFICE SWhL'H RESETTING MECHANISM Axel Gunnar Forsberg, Chicago, Ill.

Application July 19, 1948, Serial No. 39,404

' Claims. (c1. zoo-97) This invention relates to a switch re-setting mechanism for use in a, timing mechanism and has for its primary object the provision of an instantaneous re-cycling or re-setting device to be used on timing relays, timing clocks, timing switches and the like.

Another object of this invention is the provision of a simplified moderately accurate timer which will be simple and inexpensive to construct and which will automatically and instantaneously re-set for another cycle of operation should the first intended cycle be interrupted. The timing mechanism of the instant invention is useful for the purpose of definitely controlling the time interval that a circuit, or circuits are energized relative to the time interval that such circuit, or circuits are de-energized.

Another object of the invention is to provide a timing device of such wide application that it can be used generally for any purpose where the time interval during which a circuit is to be operated or not operated is of importance. The time interval during which the cycle of operation takes place can be readily adjusted.

A particular feature of this invention is the provision of a worm gear with a matched worm which is slidable in a sleeve and on a squared drive shaft and rotatable therewith and, which when driven up said sleeve and shaft a predetermined distance will be caused to actuate a locking bar which locking bar will in turn release or break contacts in the conductive wire leading to the motor driving the shaft. This vertical movement of the Worm in the sleeve may be adjusted for any desirable timed interval.

Another feature of this invention is the provision of a novel means for locking and unlocking a worm gear which enmeshes the worm slidable in a sleeve on the drive shaft so that locking said worm gear against rotation will begin the cycle of operation of the timer while the unlocking of the worm gear will stop the cycle of operation and instantaneously re-cycle or reset, that is, allowing the worm to fall down by gravity to its original pre-set position.

These, together with various ancillary objects and features of the invention which will later .become apparent as the following description motor and an electromagnet, some parts being shown in elevation;

Figure 2 is a horizontal sectional view taken substantially in the plane of section line 22 of Figure 1;

Figure 3 is another horizontal sectional view taken substantially in the plane of section line 3-3 of Figure 1; V

Figure 4 is a wiring diagram of the circuit employed in Figure l; and,

Figure 5 is a plan view of the contacts taken from the plane of section line 5-5 of Figure 1 and looking in the direction of the arrows.

Specific reference is now made to the drawings. In the several views in the accompanying drawings and in the following specification, reference characters indicate corresponding elements throughout.

Indicated generally at H] is a motor having a squared drive shaft [2. The motor I0 is suitably secured to a housing [4 by means of bolts l6. Conductive wires l8 and 20 conduct current to the motor I 0 from an electric source (not shown). The conductive wire 20 has interposed therein a 5 fixed contact 22 and a movable contact 24.

Suitably secured to a frame 26 by means of bolts 28 is an electromagnet 30 having a pair of conductive wires 32 and 34 in operative engagement respectively with the conductive wires 20 and I8. The conductive wire 32 has interposed therein a conventional switch 36.

Suitably and removably secured to the frame member 26 by means of a bolt 38 is a bottom frame portion 40. Pivoted to the frame portion 40 by means of a suitable pivot pin 42 and adjacent the electro-magnet 30 is a magnetizable member 44 to the top of which is secured a substantially L-shaped arm 46 having a depending hook member 48 at the free end thereof and extending into the housing [4.

Pivoted to the pivot pin 42 but independent in its movement from the movement of the magnetizable member 44 is a bracket 58 which at its upper end is connected to the movable contact 24 as at 52. Adjacent the upper end of the bracket is a vertical transverse bearing portion 54, preferably made of insulating material and secured to the upper and lower portions of the bracket 50 by means of suitable bolts 56.

Pivotally secured as at 60 to a wall of the housing [4 adjacent the motor I 0 and extending longitudinally therethrough is a locking bar 58 having a slot 62 to allow freedom of movement of the locking bar 58 about the drive shaft l2. Positioned in the housing M in alignment with the spindle I2 is a sleeve member 64 in which is slidably secured a worm 66 having an axial bore 68 extending therethrough which is open at the top and closed at the bottom. The bore 68 is, in effect, a drilled out round hole large enough and deep enough to allow the drive shaft I2 to enter into it as the worm 65 slides up towards the locking bar 58. The top of the worm gear 66 is preferably screw threaded to retain a cap thereon through the top of which is machined a square hole to fit the drive shaft.

Engageable with the worm 66 through a vertical slot 12 in the sleeve 64 is a worm gear H i 1' rotatably mounted as at 16 to awall of the housing I4. Y Pivotally secured as at 18 to a wall of the hous this art.

the weight of the bracket 50 pulls the moving contact 24 out of engagement with the fixed contact 22 thus breaking the circuit leading to the motor ID. The cycle may then be repeated in the manner set forth hereinabove.

In view of the foregoing description taken in conjunction with the accompanying drawings it is believed that a clear understanding of the device will be quite apparent to those skilled in A more detailed description is accordingly deemed unnecessary;

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention the same is susceptible to certain changes fully compre- 'hended by the spirit of the invention as herein ing [4 is a second vertically disposed matching worm or catch'sfl the free end of which is proximate the hook member 48. Interposed between the catch 80 and the sleeve member 64 is a spring 82 which normally urges the catch {it into engagement with the worm gear .75 to retain the latter in locking position against rotation. The

.bottom of the frame portion ie beneath the sleeve member 64 is preferably screw threaded to engageably receive a setv screw 8% the free end of. which abuts the bottom portion of the worm 68 and constitutes a means for adjusting the vertical movement of the worm 56 on the shaft i2 a predetermined distance in relation- I ship to a .desiredtime set.

In practical operation, the device of the instant invention functions in the following, manner. After first having adjusted the :set screw 84 in accordance with a predetermined time set, the switch 36 is actuated whereby the energized electro-magnet ac attracts the magnetizable member 44. While the magnetizable. member 44 moves in the direction of the electro-magnet, thearm 46 thereon strikes the bearing member 54 associated with the bracket 59 moving the contact 24 into en gement with the fixed contact 22. Also, the hook member 68 on the arm 46 pulls the second worm 80 out of engagement with the worm gear 14. The switch 36 is again actuated whereupon the electro-magnet Bil is tie-energized and the magnetizable member M falls back allowing the catch 89 to engage the worm gear M against rotation. The timing mechanism begins its operation at this point.

Contacts 22 and 24 being in engagement, the

motor it] drives the shaft [2 which in turn engages the first worm 665 which in turn rotates, and because the worm gear M is locked against rotation, it will travel up the shaft l2, and Eat the end of the stroke the nut Iii will strike the locking bar 58. It should be mentioned at this point that when the arm 48 at first engaged the bearing member 54 to move the movable contact 24 into engagement with the fixed contact 22, clearance was provided for the locking bar 53 to fall into the position shown in solid lines in Figure 1 locking the contact 24 against the contact 22 to complete the circuit through the motor It). At the .end of the stroke, as mentioned hereinabove, when the nut 10 on the moving worm 6B described and the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. In a timing mechanism including a supp0rting. frame, an electric. motorhavinga drive shaft, conductivewires interconnecting thermotorwith .a source of current, a fixed contact and a movable contact connected :with one of the conductive wires, an ve'lectro:ma net, conductive wires including a switch interconnecting-the source with the magnet and ,a .pmagnetizable member pivotedytogthe frame adjacent. the electro-magnet; a switch re-setting mechanism comprising, a worm gear, rotatable .on said frame, a matched and. enmes'hingfirst worm slidable on and ,engageable with said drive shaft for. vertical movement thereon, a sleeve slidably securing said first worm, means for locking said worm gear against rotation, a bracket pivoted to said frame and supporting said movable contact, and a locking bar pivoted to said ,frame above said worm gear engageable with said bracket for releasably retaining said'movable contact engagement with said contact.

2. The combination oi claim 1 wherein said means carried by said magnetizable member includes a second worm pivoted to saidframe adjacent said worm gear,' -an arm secured to said magnetizable member having a hook thereon for engaging said second worm, and resilient means normal-1y :urging said second worminto locking engagement with saidwormygear.

3. The combination or claim 1 "wherein said limiting means includes aset screw engageable with said first worm.

4. The combination oi claim '3 wherein said means includes a catch pivoted to said .irame adjacent said worm gear, an arm secured to said magnetizable member having .a hook thereon for engaging said catch, and resilient means normally urging said catch into locking engagement with said worm gear. 7

5. The combination oixclaim 4 wherein said bracket includes a bearingportion engageable with said locking bar and said arm.

AXEL GUNNAR FOBSBERG.

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